Nondestructive determination of trace element speciation in coal and coal ash by XAFS spectroscopy

1993 ◽  
Vol 7 (4) ◽  
pp. 482-489 ◽  
Author(s):  
Frank E. Huggins ◽  
Naresh Shah ◽  
Jianmin Zhao ◽  
Fulong Lu ◽  
G. P. Huffman
Keyword(s):  
Trace Element ◽  
Coal Ash ◽  
Xafs Spectroscopy ◽  
Nondestructive Determination ◽  
Element Speciation

Trace Element Speciation in Poultry Litter

2003 ◽  
Vol 32 (2) ◽  
pp. 535 ◽  
Author(s):  
B. P. Jackson ◽  
P. M. Bertsch ◽  
M. L. Cabrera ◽  
J. J. Camberato ◽  
J. C. Seaman ◽  
...  
Keyword(s):  
Trace Element ◽  
Poultry Litter ◽  
Element Speciation

scholarly journals Enhancement of a New Methodology Based on the Impulse Excitation Technique for the Nondestructive Determination of Local Material Properties in Composite Laminates

2020 ◽  
Vol 11 (1) ◽  
pp. 101
Author(s):  
Carlo Boursier Niutta
Keyword(s):  
Resonant Frequency ◽  
Elastic Properties ◽  
Composite Laminates ◽  
Concentrated Mass ◽  
Modal Shape ◽  
Nondestructive Determination ◽  
Material Orientation ◽  
Impulse Excitation ◽  
Clamping System

A new approach for the nondestructive determination of the elastic properties of composite laminates is presented. The approach represents an improvement of a recently published experimental methodology based on the Impulse Excitation Technique, which allows nondestructively assessing local elastic properties of composite laminates by isolating a region of interest through a proper clamping system. Different measures of the first resonant frequency are obtained by rotating the clamping system with respect to the material orientation. Here, in order to increase the robustness of the inverse problem, which determines the elastic properties from the measured resonant frequencies, information related to the modal shape is retained by considering the effect of an additional concentrated mass on the first resonant frequency. According to the modal shape and the position of the mass, different values of the first resonant frequency are obtained. Here, two positions of the additional mass, i.e., two values of the resonant frequency in addition to the unloaded frequency value, are considered for each material orientation. A Rayleigh–Ritz formulation based on higher order theory is adopted to compute the first resonant frequency of the clamped plate with concentrated mass. The elastic properties are finally determined through an optimization problem that minimizes the discrepancy on the frequency reference values. The proposed approach is validated on several materials taken from the literature. Finally, advantages and possible limitations are discussed.

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